15-Year-Old Vulnerability in strongSwan VPN Allows Service Crash Attacks

A 15-year-old vulnerability in strongSwan, an open-source VPN solution, allows attackers to crash VPN services via an integer underflow bug in the EAP-TTLS plugin. The flaw affects multiple versions of strongSwan, though specific versions or a CVE identifier were not disclosed in the report. Discovered by security researchers at Bishop Fox, the issue is classified as a "ghost bug" due to its long-undetected presence. Exploitation requires no authentication and can disrupt VPN connectivity globally. The impact is limited to service crashes rather than remote code execution or data compromise.